The Democratic People's Republic of Korea (DPRK)'s National flag waves on the embassy building in Moscow, Russia, Oct. 30. EPA-Yonhap

North Korean troops deployed to Russia were assessed to have been assigned to Moscow's airborne brigade and marine corps on the ground, with some of the North's soldiers having already entered combat, South Korea's spy agency told lawmakers Wednesday.

The National Intelligence Service (NIS) presented the assessment during a closed-door meeting of the parliamentary Intelligence Committee, according to People Power Party Rep. Lee Seong-kweun and Democratic Party of Korea Rep. Park Sun-won, who attended the session.

"North Korean troops were assessed to have been relocated to Kursk in late October after completing local adjustment training in northeastern Russia," the NIS told the lawmakers.

"Having been assigned to Russia's airborne brigade or marine corps, (some) are undergoing training in tactics and drone response, while others are assessed to have participated in combat," the spy agency said.

The NIS also told the lawmakers that North Korean troops, having entered combat, may have suffered casualties or wounds, adding that efforts are under way to determine the details of the combat circumstances and the extent of the damage.

Seoul and Washington have previously said that North Korean troops, dispatched to Russia's western front-line Kursk region, have begun engaging in combat operations against Ukrainian forces despite criticism that their introduction onto the battlefield could broaden the war and affect security in Europe and the Indo-Pacific.

Citing varying numbers of North Korean equipment operation forces, the agency estimated the size of the troop dispatch to be between 12,000 and 15,000, adding additional troop deployment could be possible at Russia's request.

"If the war prolongs, it would lead to increased troop casualties, making it possible for Putin to request additional deployments from North Korea," the NIS said.

Prolongation of the war is also feared to increase Russia' dependency on North Korea, raising the chances of Moscow transferring more sophisticated weapon technology to the North, it said, adding that "an early conclusion of the war would be desirable."

The NIS also confirmed North Korea's exports of long-range artillery to Russia, including 170 mm self-propelled howitzers and 240 mm multiple rocket launchers. North Korea has previously been reported to have shipped artillery shells and short-range ballistic missiles to Russia.

The spy agency additionally noted that North Korean Foreign Minister Choe Son-hui may have had a "very important and sensitive" discussion with Russian President Vladimir Putin during her visit to the country in early November, adding that it may not have been a mere courtesy meeting.

Choe had a surprise meeting with Putin on Nov. 4 during her visit to Russia, demonstrating the elevated closeness between their countries amid North Korea's deployment of troops to Russia to fight in its war against Ukraine.

The NIS also suggested the possibility that North Korean leader Kim Jong-un may visit Russia. (Yonhap)